Fair Value (Fair Value Measurement - Reconciliation of Level 3 Assets And Liabilities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	$ 50	$ 99
Net realized/unrealized gains (losses) included in earnings, Assets	3	1
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0
Purchases, Assets	0	0
Sales, Assets	0	0
Issuances, Assets	1	0
Settlements, Assets	(9)	(19)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	3
Fair Value, Assets, Ending balance	45	84
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0
Loans Held-for-Sale [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	3
Net realized/unrealized gains (losses) included in earnings, Assets	0
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0
Purchases, Assets	0
Sales, Assets	0
Issuances, Assets	0
Settlements, Assets	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0
Fair Value, Assets, Ending balance	3
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0
Retained Interest [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	47	100
Net realized/unrealized gains (losses) included in earnings, Assets	3	1
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0
Purchases, Assets	0	0
Sales, Assets	0	0
Issuances, Assets	1	0
Settlements, Assets	(9)	(17)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Fair Value, Assets, Ending balance	42	84
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0
Interest Rate Contract [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Net Derivative Asset (Liability), Beginning balance		(1)
Gain (Loss) Included in Earnings, Net Derivative Asset (Liability)		0
Gain (Loss) Included in Other Comprehensive Income (Loss), Net Derivative Asset (Liability)		0
Purchases, Net Derivative Asset (Liability)		0
Sales, Net Derivative Asset (Liability)		0
Issuances, Net Derivative Asset (Liability)		0
Settlements, Net Derivative Asset (Liability)		(2)
Transfers out of Level 3, Net Derivative Asset (Liability)		3
Fair Value, Net Derivative Asset (Liability), Ending balance		0
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		$ 0